Dredges are used to increase the depth of rivers and bodies of water for recreational purposes or for laying pipes in the river bed at an increased depth so that they will not interfere with water vehicles normally using the body of water.
Heretofore, problems have occurred in attempting to dredge narrow bodies of water such as a stream or river because the standard dredge is pivoted about an aft point of the barge. Therefore when using a standard barge in a narrow stream, the bow of the barge will strike the bank of the stream before the cutter does preventing the undercutting of the bank.
Barges have been developed having ladder type cutters which are pivotally secured to the bow of the barge making the cutter rotatable as the barge moves forward such as the type described in U.S. Pat. No. 2,963,801. However, these barges are restricted in size because the trunnion cannot support the weight of the ladder and suction pipe which cause shear forces on the trunnion greater than the trunnion can withstand. The restriction to smaller dredging machines limits their use in field operations because of their inability to move large quantities of silt and other material in the shortest period of time.